Pablo Neira Ayuso | 836382d | 2021-06-16 22:25:05 +0200 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0-only |
| 2 | #include <linux/kernel.h> |
| 3 | #include <linux/init.h> |
| 4 | #include <linux/module.h> |
| 5 | #include <linux/netlink.h> |
| 6 | #include <linux/netfilter.h> |
| 7 | #include <linux/netfilter/nf_tables.h> |
| 8 | #include <net/netfilter/nf_tables_core.h> |
| 9 | #include <net/netfilter/nf_tables.h> |
| 10 | |
Pablo Neira Ayuso | 33a24de | 2022-01-09 17:11:14 +0100 | [diff] [blame] | 11 | struct nft_last { |
| 12 | unsigned long jiffies; |
| 13 | unsigned int set; |
| 14 | }; |
| 15 | |
Pablo Neira Ayuso | 836382d | 2021-06-16 22:25:05 +0200 | [diff] [blame] | 16 | struct nft_last_priv { |
Pablo Neira Ayuso | 33a24de | 2022-01-09 17:11:14 +0100 | [diff] [blame] | 17 | struct nft_last *last; |
Pablo Neira Ayuso | 836382d | 2021-06-16 22:25:05 +0200 | [diff] [blame] | 18 | }; |
| 19 | |
| 20 | static const struct nla_policy nft_last_policy[NFTA_LAST_MAX + 1] = { |
| 21 | [NFTA_LAST_SET] = { .type = NLA_U32 }, |
| 22 | [NFTA_LAST_MSECS] = { .type = NLA_U64 }, |
| 23 | }; |
| 24 | |
| 25 | static int nft_last_init(const struct nft_ctx *ctx, const struct nft_expr *expr, |
| 26 | const struct nlattr * const tb[]) |
| 27 | { |
| 28 | struct nft_last_priv *priv = nft_expr_priv(expr); |
Pablo Neira Ayuso | 33a24de | 2022-01-09 17:11:14 +0100 | [diff] [blame] | 29 | struct nft_last *last; |
Pablo Neira Ayuso | 836382d | 2021-06-16 22:25:05 +0200 | [diff] [blame] | 30 | u64 last_jiffies; |
| 31 | int err; |
| 32 | |
Vasily Averin | 42193ff | 2022-04-02 12:50:37 +0300 | [diff] [blame] | 33 | last = kzalloc(sizeof(*last), GFP_KERNEL_ACCOUNT); |
Pablo Neira Ayuso | 33a24de | 2022-01-09 17:11:14 +0100 | [diff] [blame] | 34 | if (!last) |
| 35 | return -ENOMEM; |
Pablo Neira Ayuso | 6ac4bac | 2021-07-05 17:45:36 +0200 | [diff] [blame] | 36 | |
Pablo Neira Ayuso | 33a24de | 2022-01-09 17:11:14 +0100 | [diff] [blame] | 37 | if (tb[NFTA_LAST_SET]) |
| 38 | last->set = ntohl(nla_get_be32(tb[NFTA_LAST_SET])); |
| 39 | |
| 40 | if (last->set && tb[NFTA_LAST_MSECS]) { |
Pablo Neira Ayuso | 836382d | 2021-06-16 22:25:05 +0200 | [diff] [blame] | 41 | err = nf_msecs_to_jiffies64(tb[NFTA_LAST_MSECS], &last_jiffies); |
| 42 | if (err < 0) |
Pablo Neira Ayuso | 33a24de | 2022-01-09 17:11:14 +0100 | [diff] [blame] | 43 | goto err; |
Pablo Neira Ayuso | 836382d | 2021-06-16 22:25:05 +0200 | [diff] [blame] | 44 | |
Pablo Neira Ayuso | 33a24de | 2022-01-09 17:11:14 +0100 | [diff] [blame] | 45 | last->jiffies = jiffies - (unsigned long)last_jiffies; |
Pablo Neira Ayuso | 836382d | 2021-06-16 22:25:05 +0200 | [diff] [blame] | 46 | } |
Pablo Neira Ayuso | 33a24de | 2022-01-09 17:11:14 +0100 | [diff] [blame] | 47 | priv->last = last; |
Pablo Neira Ayuso | 836382d | 2021-06-16 22:25:05 +0200 | [diff] [blame] | 48 | |
| 49 | return 0; |
Pablo Neira Ayuso | 33a24de | 2022-01-09 17:11:14 +0100 | [diff] [blame] | 50 | err: |
| 51 | kfree(last); |
| 52 | |
| 53 | return err; |
Pablo Neira Ayuso | 836382d | 2021-06-16 22:25:05 +0200 | [diff] [blame] | 54 | } |
| 55 | |
| 56 | static void nft_last_eval(const struct nft_expr *expr, |
| 57 | struct nft_regs *regs, const struct nft_pktinfo *pkt) |
| 58 | { |
| 59 | struct nft_last_priv *priv = nft_expr_priv(expr); |
Pablo Neira Ayuso | 33a24de | 2022-01-09 17:11:14 +0100 | [diff] [blame] | 60 | struct nft_last *last = priv->last; |
Pablo Neira Ayuso | 836382d | 2021-06-16 22:25:05 +0200 | [diff] [blame] | 61 | |
Pablo Neira Ayuso | 33a24de | 2022-01-09 17:11:14 +0100 | [diff] [blame] | 62 | if (READ_ONCE(last->jiffies) != jiffies) |
| 63 | WRITE_ONCE(last->jiffies, jiffies); |
| 64 | if (READ_ONCE(last->set) == 0) |
| 65 | WRITE_ONCE(last->set, 1); |
Pablo Neira Ayuso | 836382d | 2021-06-16 22:25:05 +0200 | [diff] [blame] | 66 | } |
| 67 | |
Phil Sutter | 7d34aa3 | 2022-10-14 23:45:58 +0200 | [diff] [blame] | 68 | static int nft_last_dump(struct sk_buff *skb, |
| 69 | const struct nft_expr *expr, bool reset) |
Pablo Neira Ayuso | 836382d | 2021-06-16 22:25:05 +0200 | [diff] [blame] | 70 | { |
| 71 | struct nft_last_priv *priv = nft_expr_priv(expr); |
Pablo Neira Ayuso | 33a24de | 2022-01-09 17:11:14 +0100 | [diff] [blame] | 72 | struct nft_last *last = priv->last; |
| 73 | unsigned long last_jiffies = READ_ONCE(last->jiffies); |
| 74 | u32 last_set = READ_ONCE(last->set); |
Pablo Neira Ayuso | 836382d | 2021-06-16 22:25:05 +0200 | [diff] [blame] | 75 | __be64 msecs; |
| 76 | |
Pablo Neira Ayuso | 32953df | 2021-07-17 10:20:08 +0200 | [diff] [blame] | 77 | if (time_before(jiffies, last_jiffies)) { |
Pablo Neira Ayuso | 33a24de | 2022-01-09 17:11:14 +0100 | [diff] [blame] | 78 | WRITE_ONCE(last->set, 0); |
Pablo Neira Ayuso | 32953df | 2021-07-17 10:20:08 +0200 | [diff] [blame] | 79 | last_set = 0; |
| 80 | } |
Pablo Neira Ayuso | 836382d | 2021-06-16 22:25:05 +0200 | [diff] [blame] | 81 | |
Pablo Neira Ayuso | 32953df | 2021-07-17 10:20:08 +0200 | [diff] [blame] | 82 | if (last_set) |
| 83 | msecs = nf_jiffies64_to_msecs(jiffies - last_jiffies); |
Pablo Neira Ayuso | 836382d | 2021-06-16 22:25:05 +0200 | [diff] [blame] | 84 | else |
| 85 | msecs = 0; |
| 86 | |
Pablo Neira Ayuso | 32953df | 2021-07-17 10:20:08 +0200 | [diff] [blame] | 87 | if (nla_put_be32(skb, NFTA_LAST_SET, htonl(last_set)) || |
Pablo Neira Ayuso | 836382d | 2021-06-16 22:25:05 +0200 | [diff] [blame] | 88 | nla_put_be64(skb, NFTA_LAST_MSECS, msecs, NFTA_LAST_PAD)) |
| 89 | goto nla_put_failure; |
| 90 | |
| 91 | return 0; |
| 92 | |
| 93 | nla_put_failure: |
| 94 | return -1; |
| 95 | } |
| 96 | |
Pablo Neira Ayuso | 33a24de | 2022-01-09 17:11:14 +0100 | [diff] [blame] | 97 | static void nft_last_destroy(const struct nft_ctx *ctx, |
| 98 | const struct nft_expr *expr) |
| 99 | { |
| 100 | struct nft_last_priv *priv = nft_expr_priv(expr); |
| 101 | |
| 102 | kfree(priv->last); |
| 103 | } |
| 104 | |
| 105 | static int nft_last_clone(struct nft_expr *dst, const struct nft_expr *src) |
| 106 | { |
| 107 | struct nft_last_priv *priv_dst = nft_expr_priv(dst); |
Pablo Neira Ayuso | 860e874 | 2023-02-28 17:09:03 +0100 | [diff] [blame] | 108 | struct nft_last_priv *priv_src = nft_expr_priv(src); |
Pablo Neira Ayuso | 33a24de | 2022-01-09 17:11:14 +0100 | [diff] [blame] | 109 | |
| 110 | priv_dst->last = kzalloc(sizeof(*priv_dst->last), GFP_ATOMIC); |
Pablo Neira Ayuso | 51edb2f | 2022-01-10 20:48:17 +0100 | [diff] [blame] | 111 | if (!priv_dst->last) |
Pablo Neira Ayuso | 33a24de | 2022-01-09 17:11:14 +0100 | [diff] [blame] | 112 | return -ENOMEM; |
| 113 | |
Pablo Neira Ayuso | 860e874 | 2023-02-28 17:09:03 +0100 | [diff] [blame] | 114 | priv_dst->last->set = priv_src->last->set; |
| 115 | priv_dst->last->jiffies = priv_src->last->jiffies; |
| 116 | |
Pablo Neira Ayuso | 33a24de | 2022-01-09 17:11:14 +0100 | [diff] [blame] | 117 | return 0; |
| 118 | } |
| 119 | |
Pablo Neira Ayuso | 836382d | 2021-06-16 22:25:05 +0200 | [diff] [blame] | 120 | static const struct nft_expr_ops nft_last_ops = { |
| 121 | .type = &nft_last_type, |
| 122 | .size = NFT_EXPR_SIZE(sizeof(struct nft_last_priv)), |
| 123 | .eval = nft_last_eval, |
| 124 | .init = nft_last_init, |
Pablo Neira Ayuso | 33a24de | 2022-01-09 17:11:14 +0100 | [diff] [blame] | 125 | .destroy = nft_last_destroy, |
| 126 | .clone = nft_last_clone, |
Pablo Neira Ayuso | 836382d | 2021-06-16 22:25:05 +0200 | [diff] [blame] | 127 | .dump = nft_last_dump, |
Pablo Neira Ayuso | b2d3065 | 2022-03-14 18:23:00 +0100 | [diff] [blame] | 128 | .reduce = NFT_REDUCE_READONLY, |
Pablo Neira Ayuso | 836382d | 2021-06-16 22:25:05 +0200 | [diff] [blame] | 129 | }; |
| 130 | |
| 131 | struct nft_expr_type nft_last_type __read_mostly = { |
| 132 | .name = "last", |
| 133 | .ops = &nft_last_ops, |
| 134 | .policy = nft_last_policy, |
| 135 | .maxattr = NFTA_LAST_MAX, |
| 136 | .flags = NFT_EXPR_STATEFUL, |
| 137 | .owner = THIS_MODULE, |
| 138 | }; |